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Author Topic: Broken exhaust manifold bolts  (Read 11061 times)

Offline dumbucket1

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Broken exhaust manifold bolts
« on: June 16, 2008, 04:13:13 PM »
Broke 2 off on cylinder 7 flush with the head on a 305. I tried and easy out on both with lots of soaking with pb blaster and heat but broke the easy out off inside both. Then I tried grinding a bolt down to a taper and then welding that to the broken bolt but my welds dont want to hold up, probably because of the easy outs that I cannot get out now. Any other suggestions?
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Offline ccz145a

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Re: Broken exhaust manifold bolts
« Reply #1 on: June 16, 2008, 04:21:22 PM »
punch and hammer, if you can find a "landing" to drive against.

or

grind a slot for a screwdriver.

either way I would try to "shock" the threads by trying to tighten first -- then try to loosen (old millwright trick).
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Offline Bitzer!

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Re: Broken exhaust manifold bolts
« Reply #2 on: June 16, 2008, 04:23:31 PM »

Grind down to a flat surface and drill them out carefully
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Offline VileZambonie

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Re: Broken exhaust manifold bolts
« Reply #3 on: June 16, 2008, 08:41:58 PM »
Quote from: Bitzer! on June 16, 2008, 04:23:31 PM

Grind down to a flat surface and drill them out carefully

This
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Offline Blazin

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Re: Broken exhaust manifold bolts
« Reply #4 on: June 17, 2008, 12:15:24 AM »
Might have to Heli Coil the holes after.
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Offline dumbucket1

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Re: Broken exhaust manifold bolts
« Reply #5 on: June 17, 2008, 01:07:53 AM »
cant really grind on anything they are recessed down slightly
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Offline Bitzer!

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Re: Broken exhaust manifold bolts
« Reply #6 on: June 17, 2008, 11:22:54 AM »
take it out and give it to a machine shop- if they !@#$ it up they'll have to sort it  ;)


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Offline VileZambonie

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Re: Broken exhaust manifold bolts
« Reply #7 on: June 17, 2008, 01:47:18 PM »
use a carbide burr on a dremel or die grinder to flatten it out.
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Offline treny

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Re: Broken exhaust manifold bolts
« Reply #8 on: June 18, 2008, 07:20:23 AM »
I have the same thing on mine and think i can drill a 5/16 hole on them and get in about 3/4 in or an inch 1/2 wouls prob do it then i will tap the holes and put 1/2 in bolts in them they will hold a heade.Also gad  couple heads break off too , i just threaded them and use them for studds..Bruce
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Offline treny

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Re: Broken exhaust manifold bolts
« Reply #9 on: June 18, 2008, 07:25:22 AM »
replacement the one above you would have to decipher that one..

I have the same thing on mine and think i can drill a 5/16 hole on them and get in about 3/4 in or an inch 1/2 would prob do it then i will tap the holes and put 1/2 in bolts in them they will hold the headers.Also had  couple bolt heads break off too , i just threaded them and use them for studds..Bruce
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Hii There , Stating another project , an 83 c10 2wd  .Frame etc is all good and have to replace dash pad and seat , some body work and Paint Prob flat blk wth a clear cote to seal it.Ill keep in touch with updates ..Bruce

Offline Blue 82

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Re: Broken exhaust manifold bolts
« Reply #10 on: June 18, 2008, 07:21:57 PM »
 PB Blaster is good, but I think this works much better.


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Offline DnStClr

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Re: Broken exhaust manifold bolts
« Reply #11 on: June 19, 2008, 08:51:01 PM »
Heat is usually the key to broken bolt removal. Is  enough bolt left to drill small holes around the "not so" EZ Out and work on getting the EZ OUT removed? Probably not, so you have to heat the bolt with a torch til RED and let it cool and do it again. The repeated heat works to separate the rust away from the bolt and sometimes the bolt can be removed that way. I use Kroil too. After all these methods we're hrowing at you, you'll probly end up following Bitzer's advice and removing the head and taking it to a machine shop.
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Offline dumbucket1

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Re: Broken exhaust manifold bolts
« Reply #12 on: June 20, 2008, 11:37:08 AM »
Ive exhausted all methods lol. I have located a set of heads for free so I think I will just use them heads.

On that note do 305's use torque to yield bolts?
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Offline VileZambonie

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Re: Broken exhaust manifold bolts
« Reply #13 on: June 20, 2008, 06:19:21 PM »
No they don't.
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Offline 78 Chevyrado

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Re: Broken exhaust manifold bolts
« Reply #14 on: June 23, 2008, 11:59:52 PM »
When drilling out the bolt, use a left-hand drill bit and you may luck out and it'll snag and break it loose as you work on it.
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